• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

another 6.5 question

H

hate my 6.5

New Member
Messages
21
Reaction score
7
Hello smart guys
I am hating my 6.5 AGAIN
1994 3500 with 6.5 TD
The truck has been sitting for the last 4 months because it will start right up and go into limp mode. I am getting 17,18,35,36 for the codes. The IP was replaced about 35000 miles ago and the PMD has been relocated and replaced several times, and all the grounds look good.
This time I have replaced it with a used but know good one and still getting the same thing.
Today I was out warming it up and noticed there is an open vacuum line laying across the engine that I believe goes to the turbo. My question is could that open line be the cause to my problems? (please say yes) It was to cold windy and dark to look for where it belongs.

As always thanks for your help
 
the crank sensor has been replace just before the IP can those 2 things go bad in 35000 miles?
 
anything's possible. Code 18 is for crank or cam sensor. Cam sensor on the 6.5 would be the optical sensor on the IP. You need to do some diagnostics before throwing parts at it. Try unplugging the crank sensor and then starting it. It will take a lot of cranking to get it to start. If it runs fine when it starts then the optical sensor is good. Then try plugging the crank sensor in and do the same with the optical sensor, again if it runs fine then the crank sensor checks out. Oh and both times when it starts it will be in limp mode, will idle fine but cut back on power etc.
 
probably more than one issue here with all the codes you have. 17 is for the map or boost pressure IRRC. 35 and 36 are IP codes. AND JUST BECAUSE GROUNDS LOOK GOOD DOESN'T MEAN THEY ARE.
 
Thanks AK
I will try that tomorrow. Is it safe to assume the open vacuum hose has nothing to do with it?
 
Did you use a new acdelco crank sensor?I've read that anything else can cause nothing but headaches.
 
Let me step in and clarify about the grounds. Don't look at them. Take them off, clean or replace the ringlets, and clean the mounting perfectly.

The wire harness grounds on top of the engine, especially the ones at the back of the engine on passanger side (auto tranny dipstick).

The battery cables - both ends. Positive cable while your at it doesn't hurt.

Live near Vegas? I could help if within 100 miles
 
I finally was able to follow AK's advice. I unplugged the optical sensor an it started, but when I unplugged the crank sensor it would not start.
I guess I am looking at a rebuilt IP, unless someone has an optical sensor laying around they want to sell for cheap.
 
I know that there are a lot of folks who go the rebuilt IP route and are happy with it. If the budget allows, consider going with a *new* IP.

Either way, make sure that the guts are ULSD compliant, but still add some lube to the fuel anyway as it should help the injectors.

Speaking of injectors . . . if they are 'close enough' to their service life, consider doing them as well while you have the lines off.
 
Thanks Jay
That's the problem I have right now,I am on disability so there is no budget for any kind of IP. Just need to get it running the cheapest way possible.
 
In that case . . .

GMPartsGiant is currently running a sale, so see if you can find the part and hope there is a discount :)
 
You must log in or register to reply here.
Back
Top